There are some books that are simply too delicate to crack open -- the last thing you want to do is destroy an ornate medieval Bible simply because you're curious about its contents. If MIT has its way, though, you won't have to stay away. Its scientists have crafted a computational imaging system that can read the individual pages of a book while it's closed. Their technology scans a book using terahertz radiation, and relies on the tiny, 20-micrometer air gaps between pages to identify and scan those pages one by one. A letter interpretation algorithm (of the sort that can defeat captchas) helps make sense of any distorted or incomplete text.